/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

// Package config provides tools to load and validate configuration data for
// Traffic Ops API tests.
package config

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"reflect"
	"strings"

	log "github.com/apache/trafficcontrol/lib/go-log"
	"github.com/kelseyhightower/envconfig"
)

// Config reflects the structure of the test-to-api.conf file
type Config struct {
	TrafficOps   TrafficOps   `json:"trafficOps"`
	TrafficOpsDB TrafficOpsDB `json:"trafficOpsDB"`
	Default      Default      `json:"default"`
	UseIMS       bool         `json:"use_ims"`
	// Sets whether or not to perform tests that must proxy to Perl
	NoPerl bool `json:"noPerl"`
	// Sets whether or not to perform tests that involve ISO generation
	NoISO bool `json:"noISO"`
}

// TrafficOps - config section
type TrafficOps struct {
	// URL - The point to the Traffic Ops instance being tested
	URL string `json:"URL" envconfig:"TO_URL"`

	// UserPassword - The Traffic Ops test user password hitting the API
	UserPassword string `json:"password" envconfig:"TO_USER_PASSWORD"`

	// User - The Traffic Ops Users
	Users Users `json:"users"`

	// Insecure - ignores insecure ssls certs that were self-generated
	Insecure bool `json:"sslInsecure" envconfig:"SSL_INSECURE"`
}

// Users "users" section of the test-to-api.conf file
type Users struct {

	// DisallowedUser - The Traffic Ops Disallowed user
	Disallowed string `json:"disallowed" envconfig:"TO_USER_DISALLOWED"`

	// ReadOnly - The Traffic Ops Read Only user
	ReadOnly string `json:"readOnly" envconfig:"TO_USER_READ_ONLY"`

	// Operations - The Traffic Ops Operations user
	Operations string `json:"operations" envconfig:"TO_USER_OPERATIONS"`

	// AdminUser - The Traffic Ops Admin user
	Admin string `json:"admin" envconfig:"TO_USER_ADMIN"`

	// PortalUser - The Traffic Ops Portal user
	Portal string `json:"portal" envconfig:"TO_USER_PORTAL"`

	// FederationUser - The Traffic Ops Federation user
	Federation string `json:"federation" envconfig:"TO_USER_FEDERATION"`

	// Extension - The Traffic Ops Extension user
	Extension string `json:"extension" envconfig:"TO_USER_EXTENSION"`
}

// TrafficOpsDB - config section
type TrafficOpsDB struct {
	// Name - Traffic Ops Database name where the test data will be setup
	Name string `json:"dbname" envconfig:"TODB_NAME"`

	// Hostname - Traffic Ops Database hostname where Postgres is running
	Hostname string `json:"hostname" envconfig:"TODB_HOSTNAME"`

	// User - database user that Traffic Ops is using to point to the 'to_test' database
	User string `json:"user" envconfig:"TODB_USER"`

	// Password - database password for the User above
	Password string `json:"password" envconfig:"TODB_PASSWORD"`

	// Port - Postgres port running that has the to_test schema
	Port string `json:"port" envconfig:"TODB_PORT"`

	// DBType - will be 'Pg' by default but tells the Golang database driver
	//          the database type
	DBType string `json:"type" envconfig:"TODB_TYPE"`

	// SSL - Flag that tells the database driver that the Postgres instances has TLS enabled
	SSL bool `json:"ssl" envconfig:"TODB_SSL"`

	// Description - database description
	Description string `json:"description" envconfig:"TODB_DESCRIPTION"`
}

// Default - config section
type Default struct {
	Session            Session   `json:"session"`
	Log                Locations `json:"logLocations"`
	IncludeSystemTests bool      `json:"includeSystemTests"`
}

// Session - config section
type Session struct {
	TimeoutInSecs int `json:"timeoutInSecs" envconfig:"SESSION_TIMEOUT_IN_SECS"`
}

// Locations - reflects the structure of the database.conf file
type Locations struct {
	Debug   string `json:"debug"`
	Event   string `json:"event"`
	Error   string `json:"error"`
	Info    string `json:"info"`
	Warning string `json:"warning"`
}

// LoadConfig - reads the config file into the Config struct
func LoadConfig(confPath string) (Config, error) {
	var cfg Config

	confBytes, err := ioutil.ReadFile(confPath)
	if err != nil {
		return cfg, fmt.Errorf("failed to read CDN configuration: %v", err)
	}

	err = json.Unmarshal(confBytes, &cfg)
	if err != nil {
		return cfg, fmt.Errorf("failed to parse configuration from '%s': %v", confPath, err)
	}

	if err := validate(confPath, cfg); err != nil {
		return cfg, fmt.Errorf("failed to validate configuration:\n%v", err)
	}

	if err := envconfig.Process("traffic-ops-client-tests", &cfg); err != nil {
		return cfg, fmt.Errorf("failed to parse configuration from environment: %v", err)
	}

	return cfg, nil
}

type multiError []error

func (me multiError) Error() string {
	var sb strings.Builder
	for _, e := range me {
		fmt.Fprintln(&sb, e)
	}
	return sb.String()
}

// validate all required fields in the config.
func validate(confPath string, config Config) error {
	var errs multiError

	var f string
	f = "TrafficOps"
	toTag, ok := getStructTag(config, f)
	if !ok {
		errs = append(errs, fmt.Errorf("'%s' must be configured in %s", toTag, confPath))
	}

	if config.TrafficOps.URL == "" {
		f = "URL"
		tag, ok := getStructTag(config.TrafficOps, f)
		if !ok {
			errs = append(errs, fmt.Errorf("cannot lookup structTag: %s", f))
		}
		errs = append(errs, fmt.Errorf("'%s.%s' must be configured in %s", toTag, tag, confPath))
	}

	if config.TrafficOps.Users.Disallowed == "" {
		f = "Disallowed"
		tag, ok := getStructTag(config.TrafficOps.Users, f)
		if !ok {
			errs = append(errs, fmt.Errorf("cannot lookup structTag: %s", f))
		}
		errs = append(errs, fmt.Errorf("'%s.%s' must be configured in %s", toTag, tag, confPath))
	}

	if config.TrafficOps.Users.ReadOnly == "" {
		f = "ReadOnly"
		tag, ok := getStructTag(config.TrafficOps.Users, f)
		if !ok {
			errs = append(errs, fmt.Errorf("cannot lookup structTag: %s", f))
		}
		errs = append(errs, fmt.Errorf("'%s.%s' must be configured in %s", toTag, tag, confPath))
	}

	if config.TrafficOps.Users.Operations == "" {
		f = "Operations"
		tag, ok := getStructTag(config.TrafficOps.Users, f)
		if !ok {
			errs = append(errs, fmt.Errorf("cannot lookup structTag: %s", f))
		}
		errs = append(errs, fmt.Errorf("'%s.%s' must be configured in %s", toTag, tag, confPath))
	}

	if config.TrafficOps.Users.Admin == "" {
		f = "Admin"
		tag, ok := getStructTag(config.TrafficOps.Users, f)
		if !ok {
			errs = append(errs, fmt.Errorf("cannot lookup structTag: %s", f))
		}
		errs = append(errs, fmt.Errorf("'%s.%s' must be configured in %s", toTag, tag, confPath))
	}

	if config.TrafficOps.Users.Portal == "" {
		f = "Portal"
		tag, ok := getStructTag(config.TrafficOps.Users, f)
		if !ok {
			errs = append(errs, fmt.Errorf("cannot lookup structTag: %s", f))
		}
		errs = append(errs, fmt.Errorf("'%s.%s' must be configured in %s", toTag, tag, confPath))
	}

	if config.TrafficOps.Users.Federation == "" {
		f = "Federation"
		tag, ok := getStructTag(config.TrafficOps.Users, f)
		if !ok {
			errs = append(errs, fmt.Errorf("cannot lookup structTag: %s", f))
		}
		errs = append(errs, fmt.Errorf("'%s.%s' must be configured in %s", toTag, tag, confPath))
	}

	if len(errs) > 0 {
		return errs
	}
	return nil
}

func getStructTag(thing interface{}, fieldName string) (string, bool) {
	var tag string
	var ok bool
	t := reflect.TypeOf(thing)
	if t != nil {
		if f, ok := t.FieldByName(fieldName); ok {
			tag = f.Tag.Get("json")
			return tag, ok
		}
	}
	return tag, ok
}

// ErrorLog - critical messages
func (c Config) ErrorLog() log.LogLocation {
	return log.LogLocation(c.Default.Log.Error)
}

// WarningLog - warning messages
func (c Config) WarningLog() log.LogLocation {
	return log.LogLocation(c.Default.Log.Warning)
}

// InfoLog - information messages
func (c Config) InfoLog() log.LogLocation {
	return log.LogLocation(c.Default.Log.Info)
}

// DebugLog - troubleshooting messages
func (c Config) DebugLog() log.LogLocation {
	return log.LogLocation(c.Default.Log.Debug)
}

// EventLog - access.log high level transactions
func (c Config) EventLog() log.LogLocation {
	return log.LogLocation(c.Default.Log.Event)
}